1. Field of the Invention
The present invention relates to an image forming apparatus using an electronic photographic system such as a copier, printer or facsimile machine, and more particularly to an image forming apparatus having a belt unit that can be attached to and detached from the main body of the apparatus.
2. Description of the Related Art
There are image forming apparatuses used in an electronic photographic system configured such that a toner image formed on an image support member is transferred to recording paper as the paper is being transported by a belt-shaped transport apparatus (called a transfer belt or a transport belt). Moreover, apparatuses that transfer a toner image formed on an image support member to paper through an intermediate transfer belt are also well known.
Belt members such as these transfer belts or intermediate transfer belts are consumable parts, and the unit comprising the belt member, specifically, the belt apparatus can be attached to and detached from the image forming apparatus main body for replacement when the operating life is finished. In addition, normally, a cleaning apparatus is installed for cleaning toner and paper dust adhering to the belt, and this cleaning apparatus is also often set up to be attached to and detached from the image forming apparatus main body together with the belt apparatus. For example, disclosed in Japanese Unexamined Patent Application Publication 2000-338744 is a simplification of the replacement procedure by replacing the intermediate transfer belt, which is a belt apparatus, together with the cleaning apparatus thereof as a single unit.
In this regard, when comparing the operational life of a belt member such as a transfer belt or an intermediate transfer belt with that of a cleaning member, the belt member generally has a longer operational life. Thus, there have been proposals such as Japanese Unexamined Patent Application Publication 2001-343838 that are configured such that the belt apparatus and the cleaning apparatus can be separately replaced according to operational life thereof.
Nonetheless, as described in paragraph [0066] of the Description of Japanese Unexamined Patent Application. Publication 2001-343838, the cleaning apparatus (neutralization cleaning apparatus 100=first container 103) is secured to the belt apparatus (transport unit 20A) with screws, and the cleaning apparatus cannot be attached and detached without first removing the belt apparatus from the image forming apparatus main body. For this reason, there is the problem of having to spend the time and labor to remove the belt apparatus even when replacing just the cleaning member, which has a shorter operating life than the belt member.
In addition, when removing the cleaning apparatus from the image forming apparatus main body or form the belt apparatus, the cleaning apparatus is tilted and the collected toner, etc. spills. In conventional image forming apparatuses, including Japanese Unexamined Patent Application Publication 2001-343838, there was the problem that the interior or surroundings of the image forming apparatus, or the hands or clothing of the user would be soiled by toner, etc falling from the cleaning apparatus unless measures were taken to prevent toner, etc. from falling out when detaching the cleaning apparatus.
Further, there was the problem in conventional apparatuses that sometimes the units were accidentally dropped during replacement, and replacing (detaching) the units was not easy.
Technologies relating to the present invention are also disclosed for example in Japanese Unexamined Patent Application Publication 2003-202728.